Android is now the most popular smartphone operating system in the US, on the basis of the number of folk using it, at least.
According to market research company Nielsen, 37 per cent of US smartphone owners have an Android-based handset, as of March this year.
Apple's iOS is second, with 27 per cent of the US smartphone population. RIM accounts for a further 22 per cent of users.
Neither company need worry too much at this stage. While Google has the biggest OS share, it's spread across half a dozen vendors whose individual shares don't come close to challenging either RIM or Apple.
In short, those two are still making the most money.
Looking at folk who acquired a smartphone in the past six months, half said they had opted for Android and a quarter went for Apple. Only 15 per cent went for RIM, suggesting that while its installed base remains strong, it's not picking up new users as successfully as Apple or the various Android phone makers.
If that trend continues, it will erode RIM's overall market share.
Windows Mobile and Windows Phone 7 combined have a share of ten per cent of the installed base of US smartphone owners, but only seven per cent of new users chose that platform during the past six months.
That covers the period WinPho 7 has been on sale, and again indicates an overall market share decline. That said, once Nokia gets its WinPho 7 handsets out, it may pick up.
Or it may still be viewed as an also-ran. Consider Nokia's other platform, Symbian, which has never been a strong player in the US smartphone market, accounting for just two per cent of those in use. Only a percentage point of recent buyers selected it.
HP's WebOS likewise remains a minority interest, holding three per cent of the installed base but accounting for only two per cent of sales in the past six months.
Nielsen says that 20 per cent of the punters it asked between January and March this year were undecided about which smartphone OS they will choose, so there's still plenty to play for. But it's hard to see momentum moving from Android and iOS to the minority platforms.
The pressure, then, is on RIM to prevent a significant slide and on Microsoft to show that it can challenge the Canadian company for third place. How Nokia will change the dynamics of that fight isn't yet clear.
Maths nuts note: Nielsen's numbers don't add up to 100 per cent due to rounding. ®